Fluid testing and analysing device and method

ABSTRACT

A fluid testing and analysing device and a method therefor are described. The device includes, from its base up and in its upstanding configuration, a tube-holder (A) for receiving at least one partially or totally transparent tube (1) so that one wall or part of a wall thereof is visible; one or more tubes (1) forming a closed testing and observation chamber, closure means (4) for each tube, with a needle (3) extending therethrough and a flange (5), surrounding the needle, of smaller diameter than the closure means; a substantially vertical raised portion forming peripheral and/or internal walls surrounding the needles (3) and advantageously higher than the distance by which the needles project above the closure means (4); and, optionally, perforatable sheathes (11) placed on the portion outside the closed chamber (1). The device is particularly useful for human and animal biology applications.

BACKGROUND OF THE INVENTION

The present invention relates to a device and a process for carrying outtests and/or analyses of fluids, notably with a view to determiningblood groups or performing compatibility tests. In particular, itrelates to a device and a process which make it possible to carry outsafe tests and analyses of fluids under simple and safe conditions,which make these tests and analyses particularly attractive.

This device and process are particularly suitable for carrying out testsand analyses without any contamination by or of the environment.

The invention relates quite particularly, but not exclusively, to adevice and a process for determining blood groups, notably in connectionwith a blood transfusion, by a visual test in the presence of a reagent.

Several types of devices are already known in the art for determining apatient's blood group or for carrying out blood compatibility tests.

Thus, EP-A-0,054,087 describes an apparatus for testing fluids depositedin layers on supports, capable of imparting a centrifugal force to saidfluids, to which is applied an appropriate antibody, in order to revealthe antigen-antibody compatibility. This apparatus is complicated tomanufacture and manipulate. It requires control by an outside energysource.

EP-A-0,104,881 describes a device for transfusion compatibility testsdesigned to be used at the bedside of a patient who is to receive atransfusion. This device can be fixed to the blood bag, and receives, bycapillarity, a specified quantity of the patient's blood, which is thencontacted with an antiserum. The porous plastic member in which thiscapillarity is exerted should be such that only non-agglutinated bloodcan continue to migrate by capillarity. Such a member, which consists ofan absorbent porous material, is not protected before being introducedinto the blood-group-revealing antiserum.

French Patent A-2,586,815 describes a device for the determination of ablood group, comprising, for visual examination of a mixture of bloodsample and test serum, at least one closed chamber and means forintroducing the blood specimen into said chamber. Means are provided toevacuate the air from the chamber through a permeable hydrophobicmembrane, in order to permit the specimen to penetrate thereinto withoutbeing opposed by an excess pressure of air. The blood from the receiveris injected by a syringe.

Document WO-A-85/05039 describes a test-tube holder comprising avacuum-creating system, wherein the tubes containing samples to betested have a plug at their upper end and an elastic stopper at theirbase designed to be perforated by a hollow needle. A partial vacuum isthen created in the tubes. The total content of each tube is thusextracted in one operation, without the possibility of partial orrepeated extractions.

Document WO-A-92/08988 discloses a complex and automated apparatus fortaking liquid test samples and simultaneously cleaning the samplingsystem of test samples. This system comprises a serum loading station, adetection station, an index table for regulating the advance of thetubes toward a collection station, a station for sampling aliquot partsand a wash station. Here again, the sampling is done by means of aneedle whose point is introduced into the respective tube, and a vacuumis then applied to the needle, by which the liquid is completelyextracted from the tube.

Document WO-A-87/01461 describes a device for determining a blood group,wherein means make it possible to insert a blood sample to be testedand/or the test serum in a closed chamber where the reaction of the testserum with the blood is observed. In practice, a moving member such as ahollow needle effects the transfer, to the chamber, of an amount ofblood determined by the degree of partial vacuum or negative pressurepreviously created in said chamber. More preferably, the devicecomprises a housing made of two parts each displaceable relative to theother and each displaceable relative to the needle, which then has twopoints perforating, respectively and successively, the wall of thesample receptacle and that of the chamber.

None of the prior art testing devices fully satisfies all the conditionscurrently required for such devices, such as optimum conditions ofreliability, manageability and safety, particularly in the area of bloodgroup determination, notably during blood transfusions.

The problems most frequently encountered during control tests andanalyses in all areas consist, in fact, of the risks of pollution of thesubstance to be analyzed and of the risks of staining or contaminationof the operator. On the other hand, the impossibility of preserving thereactions in time prevents storage of previously obtained results.

More particularly in the medical domain, the possibility of viralcontaminations could sometimes make it awkward, even dangerous for themanipulator to do a blood compatibility check just before a transfusion,a check consisting in verifying the correlation between the patient'sblood (recipient) and that contained in the blood bag (donor) designedto be transfused into the patient. In practice, the currently availabledevices do not offer all the advantages that are expected in thisregard. Nor do they provide total safety with regard to the assignmentof the results and their follow-up.

Hence a need existed for a reliable, safe and easily manipulable devicefor performing control tests and analyses, a device which can be used inall areas and particularly in human and veterinary biology.

It has now been found, unexpectedly, that these advantages, as well asothers which will become more obvious on reading the followingdescription, are offered by a device and process according to thepresent invention.

SUMMARY OF THE INVENTION

The object of the present invention is to provide such a device and aprocess for putting it into practice, facilitating better meeting thelegitimate requirements of users and enabling the latter to work morecomfortably and with greater peace of mind in obtaining results that arenot disturbed by external causes and are completely safe.

The object of the present invention is also to provide a device and atesting and analytical procedure which exempts the user from complexmanipulations and thus extends the range of its use to all persons, evento those without specialized training, and in all areas.

Another object of the present invention is to provide such a device inwhich there is no need to create vacuum or negative pressure in the testchamber and observation chamber.

In effect, it has appeared that, unexpectedly, the device according tothe invention provides a simplicity, safety and reliability of use whichcould not be obtained until now, and which are achieved even when usingpersonnel without special training.

These and other objects are achieved by a device for carrying out testson a fluid sample comprising:

(a) at least one reaction tube, said reaction tube having a wall that isat least partially transparent, said reaction tubes having an opening ata top end thereof;

(b) a tube holder having said at least one reaction tube disposedtherein with a transparent portion of the wall thereof visible fromoutside of the holder;

(c) at least one closure disposed in the opening of said at least onereaction tube;

(d) at least one needle extending through the at least one closure andproviding a connection for passage of fluid from outside the reactionreaction tube into an interior space within the at least one reactiontube; and

(e) a substantially vertical raised portion forming walls surroundingthe needle and defining a space surrounding the needle for receiving asample container, wherein the closure interacts with a deformableportion of a perforable sample container received with the device withthe needle perforating the perforable portion of the sample container topress against the deformable portion of the sample container causingfluid in the sample container to be driven through the needle into theinterior space with the reaction tube.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 represents, in schematic longitudinal section taken along amedian vertical plane, an embodiment of the device of the invention inthe upright position;

FIG. 2 is a schematic cross-sectional view of the device according toFIG. 1;

FIG. 3 is a partial sectional view of a housing for flexible tube;

FIG. 4 is a schematic cross-sectional view taken along a median verticalplane of the device according to FIG. 1, in the upright position; and

FIG. 5 is a partial schematic sectional view of a variant of housing,snapped onto a testing and/or analytical device according to FIG. 1,with only the upper part of said housing being shown.

DETAILED DESCRIPTION OF THE INVENTION

The primary object of the invention is a device for performing testsand/or analyses of fluids, comprising at least one closed chamber and atleast one needle for perforating the fluid sample receptacles, andcomprising, from its base up in an upright position:

a tube holder for receiving at least one partially or totallytransparent tube, so that one wall or part of a wall thereof is visible;

at least one tube designed to form a closed chamber for a test and forobservation thereof;

closure means for each tube, comprising, in their center, a needleextending therethrough and with its point facing upwards, and at thebase thereof, on the upper surface of said closure means, a centralraised part or flange surrounding the needle and having a smallerdiameter than the diameter of said closure means; and

a substantially vertical raised portion forming peripheral and/orinternal walls surrounding the needles and advantageously higher thanthe distance by which the needles project above said closure means; and

optionally, perforable sheaths placed on the part of the needles outsidesaid closed chamber. This device is designed to be used in cooperationwith

sampling tubes of the fluid to be tested or of test fluid, comprising aperforable and deformable closure means, and/or

flexible perforable hoses welded at their ends and containing a sampleof fluid to be tested or test fluid.

For use of flexible hoses, the device is advantageously completed by amember forming a housing for their introduction over at least one needleto permit their non-throughgoing perforation by at least one of theabove needles.

According to a preferred embodiment, the device according to theinvention comprises a tube holder combined with at least one memberforming a housing for combined use of test tubes and flexible testsample hoses.

The invention also relates to a process for carrying out tests and/oranalyses of fluids, consisting in the use of a device as described aboveand below, and comprising the steps of:

perforation and deformation under pressure of the closure means of atube or of a flexible hose containing a sample of fluid to be tested orof test fluid, for introduction of an appropriate amount of test samplein at least one closed chamber comprising a closure means provided witha perforating and introduction needle;

repetition of the above step until all the test reagents and/or all thesamples to be tested or to be analyzed have been introduced in therespective closed chambers; and

examination of the reaction chambers in question.

Below, the invention is described in more concrete terms by reference tothe attached drawings, which in no way limit said invention, and inwhich:

For greater convenience, the invention will be described below byreferring most frequently to such use. However, it should be understoodthat this particular application serves only to give a more preciseillustration of the invention, and in no way limits the scope thereof.

As shown in FIGS. 1 and 2, the device according to the inventioncomprises a tube holder A making it possible to maintain, in the uprightposition, at least one tube 1, which may or may not already contain areagent 2 that is appropriate for the test to be carried out. Thereagent may be introduced previously into the tube 1 before itsobturation. This should be the case if said reagent is solid.

The tube holder A may be made of any material, preferably of plasticmaterial, and it should leave visible at least portions of the wall ofthe tubes which it holds. In practice, this can be achieved either bychoosing an intrinsically transparent material for said tube holder, orby having no wall in the tube holder opposite the portions of tube wallswhich must meet this condition. All or part of the tube holder and/ortubes may be, e.g., of glass or a plastic material such aspolypropylene, polycarbonate, polyethylene, or others.

The tubes 1 may be introduced into appropriate receptacles of the tubeholders or constitute an integral part thereof, advantageously in theform of cells arranged in the tube holder itself. They may have anygiven cross-section, e.g., square, triangular, circular, polygonal orother. An ovoid cross-section is preferred, so as not to createcapillarity and electrostatic adhesion problems of the reagents andreaction products at the corners of a section having right angles oracute angles.

Tubes of small cross-section are preferred, where a small volume ofreagent suffices. The height of the tube facilitates the "to-and-fromovement" of the reaction mixture when an alternating rocking movementis imparted to the device, and thus optimizes the "reading" of thereaction.

The upper orifice of the tube 1 is traversed in its center by a needle 3which is made integral with a closure means 4 appropriate for pluggingthe orifice of said tube 1. This closure means may be of any materialconventionally used for said function; it should be sufficiently rigid.According to a preferred embodiment, the needle/closure means assembly,as well as possibly the central raised part or flange 5 above it, may beobtained by molding techniques known to persons skilled in the art. In avariant, said flange may be detachable and be left to slide freely onthe needle, or preferably it may be fixed in an adherent manner theretoor to the surface of the plug facing the point of the needle.

The raised portion may be realized by appropriate prolongation of thewalls of the tube holder in the upright position, in direct prolongationthereof, or displaced relative to them. It is advantageously profiled insuch a way, or has means on its walls facing the interior of the devicethat are so arranged, that a guidance is assured for the tubes 6 and/orhousings 7 containing samples to be tested.

As shown in FIG. 3, the housing 7 preferably consists of a block ofdimensions suitable for its introduction, such as described above, andcomprising, in the position of use, either a U-shaped channel 8 openingout to the top, or a substantially linear channel opening out laterally,as well as at least one nontraversing and substantially vertical bore 9,putting into communication said channel and the exterior on the lowersurface of the housing.

According to an advantageous embodiment, the housing 7 comprises atleast two bores and, optionally, it also has means for exertingpressures on the flexible hose 10, once the latter has been introducedinto the housing, and means 12 for locking the housing into its positionof use and preferably for preventing it from being removed afterperformance of the test, e.g., means in the form of reverse-lock pins inor near the guides used for its introduction into the tube holder.

To further improve the safety of the device with regard to the risk ofstaining or contamination, as well as to eliminate the risks ofevaporation of the reagent before use, it is advantageous to provide theportions of the needles external to the test tubes with a perforablesheath 11 which is tight to liquids and preferably also to gases, e.g.,one made of flexible plastic material such as polyvinyl chloride orrubber latex. This sheath, which in practice has the general form of acondom, is designed to be perforated by the needle, and is then foldedinto an accordion shape between the base of the needle and the plug ofthe sampling tube, where it contributes to improving the tightness, ifnecessary.

With regard more particularly to the domain of tests and analyses inhuman and veterinary biology, it has been found--as will be shownfurther on--that the device according to the invention is especiallysuitable for use in combination with all types of conventional samplingtubes with closure systems having the required perforability andflexibility characteristics.

To use the device according to the invention, a stoppered tubecontaining a sample is placed in an upside down position on the point ofa needle of one of the tubes of the tube holder and a downward verticalpressure is applied thereto so as to deform the flexible stopper of thistube by said flange, in order to exert therein a fluid pressuresufficient to have one or more drops of the sample emerge from saidtube. Said operation may be repeated as many times as necessary.Likewise, if the sample is contained in a flexible hose, the latter isintroduced in a housing unit such as described above, which itself isbrought opposite to at least one needle to permit a nontraversingperforation of the hose by said needle, and at least one pressure isexerted on the hose on at least one end thereof projecting from thehousing, said pressure being applied either manually or by assistedpressure, or by means of a pressing member integral with the housing, orby downward vertical pressure on the housing itself, and doing so asmany times as necessary. Here again, each pressure exerted on the hosehas the effect of forcing at least one drop of sample fluid to passthrough the channel of the needle into the corresponding tube, forming aclosed reaction chamber.

The reaction showing the result of the test is of a known type. It isthe result of a change in the mixture of the reagent contained orpreviously introduced into the reaction chamber and the sample to beanalyzed, e.g., of blood whose blood group is being determined orchecked in this manner. It makes use of either solid or liquid reagents,possibly on a support, reagents which are capable in the presence of asample responding to the test of eliciting either a colored reaction oragglutination or other types of reactions observable by the human eyeand/or by means of evaluation apparatus, such as, e.g., a cloudingmeasurable by turbidimetry, or hemolysis. In practice, the deviceaccording to the invention is designed to be used for observing the testresults directly by the naked eye.

According to the inventions identification of the samples tested isfacilitated by the possibility offered by the tube holder of receivingclear or coded information on at least some of its visible surfaces,information suitable for perfect monitoring and increased safety of thetests. In addition, this device may, it desired, be connected to anautomated recognition system, advantageously on the basis of numericalcriteria.

According to a preferred variant for medical applications, particularlyfor blood transfusion, this device may be equipped with a chart or othersupport provided with a chip and capable of preliminary storage, byappropriate means, of the digital imprint and other data relating to thepatient to be transfused and/or data concerning the bag of blood to betransfused.

The device according to the invention may be used for all types oftests, particularly but not exclusively in human or veterinary biology,especially for virological tests (e.g., HIV, among others) orbacteriological tests (e.g., in urinalyse. or cerebrospinal fluidpuncture).

The tests carried out in this manner respond well to the requirements ofinstantaneousness and rapidity of results, while providing themanipulator user with a guarantee that there are no risks ofcontamination. Then, the reactions used may be hemagglutinationreactions, latex agglutination reactions, or any other type of reactionthat can be interpreted by the naked eye.

The simplicity of use of this device, which is ready for use, permitsits use by all persons, even by those without any special knowledge ofbiology, and particularly by all hospital physicians, privatephysicians, nurses, patients themselves, or private persons.

An illustrative example of an application in this area is given below,by reference to FIG. 4 of the appended drawings.

The device according to the invention in the variant of embodiment citedwas used to carry out, immediately before a transfusion, a bloodcompatibility check, commonly called "final test at the patient'sbedside." This test consisted in verifying the correlation between thepatient's blood (recipient) and that contained in the bag of blood(donor) designed, in principle, to be transfused to the patient.

A sample container with two contiguous chambers as shown in FIG. 5,capable of being simultaneously activated by perforation of a hoseinitially connected to the transfusion bag and introduced by means of anappropriate housing was used, respectively, for a reaction of thedonor's blood with an anti-A test serum and a reaction with an anti-Btest serum.

The two other chambers, each having a guide for the introduction ofsample tubes, were used, respectively, for a reaction of the patient'sblood with an anti-A test serum and a reaction with an anti-B testserum.

The samples originated, respectively:

from a blood sample tube of a type generally used in medicine, having aperforable and deformable closure means,

from a tubing commonly called "hose or tube" integral with thetransfusion bags and containing a small volume of blood.

They were contacted in the respective closed chambers with a test serumthat was already present therein, namely with the anti-A test serum orthe anti-B test serum, depending on the case, by perforation applyingpressure on the needles carried by the respective reaction chambers asindicated above, so as to make at least one drop of blood fall each timeinto the reaction chamber.

For better performance of the agglutination reactions, the device was"moved to and fro" several times, to make it possible to spread thereaction product over nearly the entire surface of a wall of the tubes.

On "reading," the presence of agglutination indicates the presence, onthe surface of the red blood cells tested, of the antigen correspondingto the antibody contained in the reaction chamber. By contrast, ahomogeneous mixture without any trace of agglutination indicates theabsence, on the surface of the red blood cells, of the antigencorresponding to the antibody contained in the reaction chamber.

The transfusion may be carried out if the results obtained in the twochambers reserved to the donor are equivalent to the results obtained inthe two chambers reserved to the recipient.

For greater safety and for recording the results without any risk ofconfusion, all or part of the surface of the device opposite to that onwhich the reading of the results is made may bear one or more labels,comprising and/or receiving useful indications.

I claim:
 1. A device for carrying out tests on a fluid samplecomprising:(a) at least one reaction tube, said reaction tube having awall that is at least partially transparent, said reaction tubes havingan opening at a top end thereof; (b) a tube holder having said at leastone reaction tube disposed therein with a transparent portion of thewall thereof visible from outside of the holder; (c) at least oneclosure disposed in the opening of said at least one reaction tube; (d)at least one needle extending through the at least one closure andproviding a connection for passage of fluid from outside the reactiontube into an interior space within the at least one reaction tube; and(e) a substantially vertical raised portion forming walls surroundingthe needle and defining a space surrounding the needle for receiving asample container, wherein the closure interacts with a deformableportion of a perforable sample container received with the device withthe needle perforating the perforable portion of the sample container topress against the deformable portion of the sample container causingfluid in the sample container to be driven through the needle into theinterior space with the reaction tube.
 2. The device according to claim1, wherein the closure comprises a base portion having a diameter forinsertion in the opening of the reaction tube, and a flange portionhaving a smaller diameter than the base portion, said flange portionsurrounding a portion of the needle and extending from the base portionof the closure outwards from the opening of the reaction tube.
 3. Thedevice according to claim 1, further comprising at least one perforablesheath disposed over the at least one needle.
 4. The device according toclaim 1, further comprising at least one sample container disposedwithin the space defined by the vertical walls.
 5. The device accordingto claim 4, wherein the sample container comprises a housing forreceiving a perforable, flexible tube containing a fluid sample saidhousing comprising a body having a channel formed therein for receivingthe perforable flexible tube and at least one bore extending from anexterior surface of the housing into said channel to provide access forperforation of flexible tube in the housing by the needle.
 6. The deviceaccording to claim 5, wherein the channel in the body of the housing isU-shaped.
 7. The device according to claim 6, wherein the closurecomprises a base portion having a diameter for insertion in the openingof the reaction tube, and a flange portion having a smaller diameterthan the base portion, said flange portion surrounding a portion of theneedle and extending from the base portion of the closure outwards fromthe opening of the reaction tube.
 8. The device according to claim 6,further comprising at least one perforable sheath disposed over the atleast one needle.
 9. The device according to claim 5, wherein theclosure comprises a base portion having a diameter for insertion in theopening of the reaction tube, and a flange portion having a smallerdiameter than the base portion, said flange portion surrounding aportion of the needle and extending from the base portion of the closureoutwards from the opening of the reaction tube.
 10. The device accordingto claim 5, further comprising at least one perforable sheath disposedover the at least one needle.
 11. The device according to claim 5,wherein at least two bores are formed in the body of the housing,further comprising means for applying pressure on a perforable, flexibletube received within the channel.
 12. The device according to claim 5,wherein the at least one reaction tube is formed as an integral part ofthe tube holder.
 13. The device according to claim 5, further comprisinga chip for storage of information concerning a patient or a sample. 14.A method for carrying out tests on a fluid sample comprising the stepsof:(a) placing the fluid sample into a perforable and deformable samplecontainer; (b) inserting the sample container into a device comprisingatleast one reaction tube, said reaction tube having a wall that is atleast partially transparent, said reaction tubes having an opening at atop end thereof; a tube holder having said a reaction tube disposedtherein with a transparent portion of the wall thereof visible fromoutside of the holder; a closure disposed in the opening of said atleast one reaction tube; a needle extending through the closure andproviding a connection for passage of fluid from outside the reactiontube into an interior space within the reaction tube; and asubstantially vertical raised portion forming walls surrounding theneedle and defining a space surrounding the needle for receiving thesample container, (c) perforating the sample container with the needleand applying pressure to deform the sample container, therebytransferring at least a portion of the fluid sample from the samplecontainer to the reaction tube for testing.
 15. The method of claim 14,wherein the reaction tube contains a reagent for reaction with thesample fluid.
 16. The method according to claim 14, wherein the closurecomprises a base portion having a diameter for insertion in the openingof the reaction tube, and a flange portion having a smaller diameterthan the base portion, said flange portion surrounding a portion of theneedle and extending from the base portion of the closure outwards fromthe opening of the reaction tube.
 17. The method according to claim 14,wherein the sample container comprises a housing for receiving aperforable, flexible tube containing a fluid sample said housingcomprising a body having a channel formed therein for receiving theperforable flexible tube and at least one bore extending from anexterior surface of the housing into said channel to provide access forperforation of flexible tube in the housing by the needle.
 18. Themethod according to claim 17, wherein the channel in the body of thehousing is U-shaped.
 19. The method according to claim 18, wherein theclosure comprises a base portion having a diameter for insertion in theopening of the reaction tube, and a flange portion having a smallerdiameter than the base portion, said flange portion surrounding aportion of the needle and extending from the base portion of the closureoutwards from the opening of the reaction tube.
 20. The method accordingto claim 17, wherein at least two bores are formed in the body of thehousing, and the device further comprises means for applying pressure ona perforable, flexible tube received within the channel.